Process and extruder nozzle for producing tubular extruded products

摘要

A process and an extruder nozzle for tubular products includes the steps of feeding pressurized material into an extruder nozzle through an inlet, and forcing this material flow through a duct formed between outer and inner nozzle components, and pressing the material flow through an annular aperture at the duct end. Material entering the extruder nozzle is distributed first by feeding into an annular expansion chamber whose cross-section is much greater than the inlet's. When the expansion chamber is completely filled with material whose pressure has become higher than the flow resistance of a homogenizing ring channel having a cross-section narrowed to and connected to the annular expansion chamber then in the homogenizing ring channel the material flow is forced to move across its entering direction, and is homogenized by the relative rotation of surfaces of the homogenizing ring channel. Helical forced movement leads the material to a drawing aperture.